Root Planing – Limitations and Goals

What Are the Expected Outcomes and Limitations ofRoot Planing? How Successful Is Root Planing in Achieving Its Goals and Objectives?

Calculus removal. Both hand- and power-driven instruments have limited utility in calculus removal from periodontal pockets. As a guideline, calculus removal becomes progressively more inefficient in sites with probing depths greater than 3 mm, and the limit of any effective instrumentation occurs in probing depths over 6 mm. These reports support the notion that closed (nonsurgical) access for scaling and root planing in pockets less than 3 mm may be as effective as open (surgical) access. When probing depths are greater than 6 mm, residual calculus is inevitable. These sites will require surgical access for effective root debridement.

The limitations in achieving the goals and objectives of root planing may be a function of either:

Root planing will reduce the biomass of pathogenic bacteria and calculus in periodontal pockets. The reduction in bacterial load will allow improved periodontal health in most cases of chronic periodontitis. Mild cases of periodontitis may not require additional surgical therapy. In more advanced cases, repeat sessions of scaling and root planing are not indicated, as they probably will not improve soft tissue health beyond that achieved by one or two sessions of therapy. Still, where surgery is indicated, presurgical scaling and root planing will improve tissue health and enhance surgical outcomes.

Removal of disease affected cementum. The cementum of the coronal third of the root ranges from 10-150 tm. It is thinnest nearest the cementoenamel junction and becomes progressively thicker toward the root apex. Because it is thin and is readily accessible to instrumentation, all cervical cementum is usually removed in 1-4 strokes of a curette. In advanced cases of periodontitis that involve the thicker cementum at the mid-root, and where clinical access may be reduced by deeper pocket depths or root anatomy, the removal of cementum is predictably less complete. Other factors that affect the amount of tooth structure removed during scaling and root planing are the forces applied at the working end of the instrument and the number of strokes with an instrument against a given root surface. Ultrasonic instruments remove less tooth structure than do hand curettes.

Both hand curettes and power-driven instruments used for root planing remove affected cementum containing endotoxin. Curettes are more effective than ultrasonic instruments in removing endotoxin from root surfaces, and under ideal conditions, hand curettes are capable of rendering root surfaces previously in contact with diseased periodontal tissues totally free of endotoxin.

Decreased probing depths and gains in periodontal attachment. As a general rule, subgingival scaling and root planing with hand- and/or power-driven instruments will yield decreases in probing depths and, in most cases, gain in periodontal attachment. Deeper periodontitis sites are more likely to gain attachment than shallow sites, and there does not seem to be a limit to pocket depth where these effects will not be observed to one degree or another. These changes usually occur within the first month following treatment and can be maintained with good oral hygiene and monthly supragingival cleanings for up to three months.

What Is Meant by Critical Probing Depth?

The downside of root planing is the observation that a loss of clinical attachment will invariably occur when shallow pockets are mechanically instrumented. Concepts of critical probing depths have emerged as decision-making guidelines for nonsurgical and surgical periodontal therapy. Scaling and root planing initial probing depths 2.9 mm will result in a net loss of periodontal attachment while performing the same procedures on pockets >2.9 mm will result in a net gain in periodontal attachment. Similarly, the critical probing depth for surgical treatment is 4.2 mm.

Judicious instrumentation to control inadvertent tissue injury is appropriate in shallow periodontal pockets during root planing . Since the injury produced by instrumentation is a painful blunt tearing of the tissues of the dentogingival junction, the use of local anesthesia for patient comfort should be avoided to minimize unwanted soft-tissue injury. Local anesthesia should be reserved for periodontitis cases where deep pockets (>6 mm) are the rule and where instrument efficiency and effectiveness is limited.

Reduce the load of pathogenic bacteria. Visual clinical measures of supragingival plaque accumulation on teeth are usually affected most by supragingival instrumentation and oral hygiene practices by the patient. Subgingival instrumentation is not a requirement for changes in visual measures. Subgingival scaling and root planing are effective in reducing the number of bacterial morphotypes associated with inflammatory disease (motile rods and spirochetes) as seen in dark- field or phase contrast microscopy. Hand, sonic, and ultrasonic instrumentation appear to be equally effective in producing these changes and in creating an environment where morphotypes associated with periodontal health (nonmotile cocci and rods) will predominate. However, these changes are not permanent, and the proportions of pocket bacterial rnorphotypes will return baseline levels in 2-3 months. Frequent professionally performed supragingival debridements will have little effect on this trend. It is clear that aibgingival instrumentation is a critical guideline in achieving the clinical goals and objectives of root planing.

The requirement for the elimination of periodontal pathogens does not appear to be absolute as clinical improvements in plaque levels, inflammation, probing depths, and attachment levels may be achieved with scaling and root planing when pathogens are reduced, but not necessarily eradicated. The observations that the goals and objectives of scaling and root planing can be achieved by only reducing the numbers of periodontal pathogens supports the notion that a critical mass of pathogenic bacteria are required before the host becomes susceptible to periodontal diseases.

Control gingival inflammation. Scaling and root planing will predictably reduce gingival inflammation. As it has been with other clinical measures of successful scaling and root planing, the instrumentation must be subgingival to achieve this outcome. Hand, sonic, and ultrasonic instruments appear to be equally effective in reducing gingival inflammation

What Is Soft Tissue Management (STM)?

In its broadest sense, STM refers to local mechanical and chemotherapeutic approaches to improving and controlling periodontal health. As such, oral hygiene instructions, the use of antimicrobial agents as mouthrinses or crevicular irrigants, subgingival scaling and root planing with hand- and power- driven instruments, correcting unserviceable dental restorations, and supragingival coronal polishing are important elements of STM. STM bears striking resemblance to the typical initial therapy periodontal treatment plans that have been used successfully for inflammatory periodontal disease control and that are included in the Parameters of Care. STM should be limited to the management of gingivitis and slight periodontitis with <2 mm of clinical attachment loss where bacterial deposits on teeth are usually accessible and can be removed efficiently and effectively.

Root concavities, root grooves, furcation invasions, and other anatomical factors that could affect the completeness of debridement are usually not an issue in these cases. Moderate periodontitis (3 or 4 mm of clinical attachment loss) and severe periodontitis ( 5 mm clinical attachment loss) cases should be considered for referral to a periodontist where issues of force control, surgical access, pocket elimination, regeneration of lost attachment, and gingival augmentation can be addressed by clinicians trained and experienced in the management of advanced periodontitis.

Chairside diagnostic instruments that measure volatile sulfur compounds, periodontal pocket temperatures, and the motility of pocket bacteria have been used in patient education STM. These methods are not described in the Glossary of Periodontal Terms nor are they included in the Parameters of Care.

Scaling and root planing are fundamental procedures in nonsurgical periodontal therapy. The target of scaling and root planing is the removal of subgingival bacteria and the removal of affected cementum. The effectiveness of scaling and root planing is limited by root anatomy, pocket depths, the skill and experience of the provider, and the overall systemic health of the patient. The outcomes of scaling and root planing include lowered plaque scores, reduced gingival bleeding scores, gain in periodontal attachment, gingival recession, and reductions in probing depths. Instrumentation of root surfaces must be subgingival in order to achieve these results.

In mild and some moderate chronic periodontitis cases, the clinical outcomes of scaling and root planing may preclude the need for periodontal surgery.